In the fabrication of circuit boards it is necessary to deburr and polish the surfaces of newly manufactured circuit boards prior to disposition of the electrical circuitry thereon. In the prior art, it has been common practice to utilize deburring machines having rotating cylindrical brushes which pass over the surface of the circuit board so as to remove undesirable burrs and surface imperfections. Such cylindrical brushes generally comprise a single shaft with a brush head extending therefrom.
Difficulties frequently arise as a consequence of variations in the pressure of the brush head against the surface of the printed circuit board. Failure to maintain proper constant pressure against the circuit board results in too little or too much abrasion of the circuit board surface. Preferably, such irregularities are eliminated such that the a smooth even surface is produced, which is accurately repeatable from board to board. Moreover, after substantial usage the central shaft of such brushes may undergo slight bending during operation. The bending of the shaft may result in uneven wearing of the board surfaces.
Accordingly, there exists a need to provide an improved circuit board deburring system which provides for close regulation of the pressure exerted on the board surface so as to enable close tolerance deburring and polishing. More particularly, there exists a need for an improved deburring system which incorporates highly sensitive means for controlling the downward pressure exerted by the rotating/oscillating brush, despite the different thickness of circuit boards.